This application is the US national phase of international application PCT/EP01/03911 filed Apr. 5, 2001, which designated the US.
The invention relates to a device for flattening pieces of meat according to the preamble of claim 1.
It has always been known for pieces of meat to be flattened, in particular if they are to be processed in schnitzel form. On the one hand, this flattening operation is carried out with the aim of increasing the size of the pieces of meat while simultaneously reducing the thickness.
In addition, the flattening operation causes the meat to become tender. Connective tissue is known to make meat tough. The flattening operation causes the fibrils to be rearranged and the connective tissue between the fibrils to tear.
Devices which, in a manner comparable to the conventional operation of beating the meat, are intended to make it possible for the pieces of meat to be flattened, have already been disclosed. Such known devices comprise two conveying belts. These conveying belts are arranged one above the other by way of a gap which decreases more and more from an inlet side to a discharge side. As a result, the pieces of meat are pressed increasingly flat during the transporting operation.
In this case, the conveying-belt surfaces are supported either by plates or by rollers or by both. There are also flattening devices which additionally comprise vibrators.
There are also processes which press two plates against one another only under high pressure.
The conveying belts have to have comparatively pronounced surface structures since, otherwise, they cannot carry along the meat in the conveying direction into the increasingly tapering gap between the two conveying belts, that is to say in the tapering direction, and otherwise the meat would slide away counter to the conveying direction with increasing tapering of the conveying belts.
It proves to be disadvantageous for such installations, however, that, although the meat is clamped between the two conveying belts, e.g. is pressed with the effect of reducing the thickness, it is not easy thus to make it possible to increase the surface area of the piece of meat. This is because the meat is pressed in firmly between the two belts, and builds up pronounced friction in relation to the belts, so as thus to counteract an increase in the surface area of the piece of meat.
In addition, the belt structure, as has been explained above, is necessarily usually fairly coarse. Fine belts do not ensure flattening success with pronounced deformation. In addition, the necessary overall length of such machines is comparatively large. Finally, the transporting speed is also comparatively low.
The object of the present invention is thus, based on the prior art explained, to provide an improved device for flattening foodstuffs, in particular slices of meat, which makes it possible to realize an optimum increase in size of the piece of meat while simultaneously reducing the thickness.
The object is achieved according to the invention by the features specified in claim 1. Advantageous configurations of the invention are specified in the subclaims.
The device according to the invention makes it possible for tender ready-to-cook schnitzels to be produced, for example, reliably and quickly. According to the invention, it is possible here to realize, in continuous operation, a high degree of meat tenderness and a permanent increase in size of the piece of meat, with the thickness simultaneously being evened out, with a low level of additional operational outlay. Since the fibrils are not severed, the juice remains in the meat. As a result the process according to the invention has considerable advantages in relation to known processes for tenderizing by cutting into the portions of the meat (making them into steaks).
Finally, it is possible to dispense with belts with pronounced structures, this ensuring that the surface of the meat is not adversely affected by pronounced corrugation.
This is ensured according to the invention by a rotating drum which has circumferentially offset rolling-out rollers or a multiplicity of beating rollers, which are preferably arranged parallel to the axis of rotation of the rotating drum.
It is possible here for the meat to be guided relatively loosely between two belts up to a flattening location in the region of the rotating drum. A pressure-relief phase, in which the meat can expand, takes place between each of the pressing phases.
An increase in surface area is also aided and assisted, according to the invention, in particular in that in each case two beating or rolling-out rollers which are arranged adjacent to one another in the circumferential direction on the beating drum are provided with coordinated surface structures. This is because the eating rollers have a circumferential groove formation, the raised ring crosspieces and the ring grooves located therebetween, which are arranged successively in the axial direction, in one beating roller being offset from those of the adjacent beating roller. In other words, the raised ring crosspieces on one beating roller, in respect of the axial length of the latter, are located precisely at those locations at which the smaller-diameter ring grooves are formed on the adjacent beating roller and vice versa. As a result of the raised locations of the beating rollers thus alternating with the lower-level locations thereof, the meat can optimally increase in size both in the longitudinal direction and in the transverse direction and thus become thinner as uniformly as possible.
A further improvement is achieved in that, at the inlet to the flattening location, it is possible to reduce the inlet angle between a counter-plate and the radius of curvature of the beating drum in that the counter-plate, rather than running rectilinearly with the tangential end oriented toward the radius of the beating drum, is formed with its abutment surface oriented concavely in relation to the beating drum. This results in kinematics comparable to a planar, i.e. rectilinear and thus tangential abutment plate, although the latter, in order to achieve the same conditions, would require the beating drum to have a considerably larger diameter than the present invention, as a result of which the overall size of the installation would be very much greater.